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(11) | EP 1 126 610 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Semiconductor active fuse operating at high supply voltage employing current oscillation |
| (57) A high-voltage semiconductor active fuse has first (QA) and second (QB) semiconductor
elements, a comparator (CMP1) for comparing the voltages of the first and second semiconductor
elements with each other, a driver (111) for supplying a control voltage to the control
electrodes of the first and second semiconductor elements according to the output
of the comparator, a first diode connected between a first input terminal of the comparator
and a low-potential power supply terminal of the comparator, and a second diode connected
between a second input terminal of the comparator and the low-potential power supply
terminal through a resistor. When detecting an abnormal current, the active fuse turns
on and off the first semiconductor element to cause current oscillations, which blocks
the conduction between an external input terminal and an external output terminal.
The active fuse needs no shunt resistor and is capable of quickly responding to an
abnormal current caused by an incomplete short circuit failure. |